Container seam locator and positioner for container printing machine

ABSTRACT

Mechanism for locating the seams where the terminal ends of containers such as steel cans are joined together in high-speed printing or decorating apparatus wherein a rotary mandrel drum must present the containers individually to offset printing blankets on a rotary printing drum in the same relative rotational position so that the seam of the can is never printed. The rotary mandrel has a series of circumferentially spaced mandrel lever assemblies with generally tangentially disposed laterally projecting mandrels thereon, mounted in line with printing blankets on the peripheral face of the rotary printing drum. The mandrel lever assemblies are provided with cam follower mechanism for engaging cam surfaces just upstream of the printing station which function to normally revolve the cans on the mandrels, and a can-engaging stop is provided which is biased to maintain engagement with each rotating can and halt further rotation thereof when the double thickness seam of the can is engaged. The additional cam surface utilized to bias the stops terminates just short of the printing station so that the cans, which have thus been positioned in preselected rotary positions on their mandrels, are now free to revolve with the mandrels, when engaged by the printing drum blankets.

United States Patent [1 1 Brown et :11.

[ 1 Oct. 2, 1973 1 CONTAINER SEAM LOCATOR AND POSITIONER FOR CONTAINER PRINTING MACHINE [75] Inventors: Gaylord W. Brown; Charles Howe, both of Beaverton, Mich.

[731 Assignee: Koehring Company, Milwaukee,

Wis.

[22] Filed: June 23, 1971 [21] Appl. No.: 155,726

US. Cl 101/40, 198/33 AB [51] Int. Cl B4If 17/22 158] Field of Search 101/35, 38-40;

[56] I References Cited UNITED STATES PATENTS 3,613,571 10/1971 Russell et a1 101/40 3,110,247 1l/1963 Simpson 101/38 R 2.528.912 11/1950 Rappaport et a1 198/33 AB 2,919,788 1/1960 Geertsen A 101 /35 UX 3,306,473 2/1967 McCoy 198/33 AB X 3,478,860 11/1969 Schick 198/33 AB 1,990,498 2/1935 Nordquist 198/33 AB UX 3,553,419 l/l97l Garrer et a1 198/33 AB X Primary ExaminerRobert E, Pulfrey Assistant ExaminerClifford D. Crowder Attorney-Learman & McCulloch [57] ABSTRACT Mechanism for locating the seams where the terminalends of containers such as steel cans are joined together in high-speed printing or decorating apparatus wherein a rotary mandrel drum must present the containers individually to offset printing blankets on a rotary printing drum in the same relative rotational position so that the seam of the can is never printed. The rotary mandrel has a series of circumferentially spaced mandrel lever assemblies with generally tangentially disposed laterally projecting mandrels thereon, mounted in line with printing blankets on the peripheral face of the rotary printing drum. The mandrel lever assemblies are provided with cam follower mechanism for engaging cam surfaces just upstream of the printing station which function to normally revolve the cans on the mandrels, and a can-engaging stop is provided which is biased to maintain engagement with each r0- tating can and halt further rotation thereof when the double thickness seam of the can is engaged. The additional cam surface utilized to bias the stops terminates just short of the printing station so that the cans, which have thus been positioned in preselected rotary positions on their mandrels, are now free to revolve with the mandrels, when engaged by the printing drum blankets.

13 Claims, 5 Drawing Figures PAIENIEWIT 2 SHEET 2 UP 3 INVENTORS GAYLORD W BROWN CHARLES E. HOWE Leznmn 6? McCulloch sum 30F 3 INVENTOR GAYLORD W. BROWN CHARLES E. HOWE BY Lemma!!! 6? McCulloah Pmminw 21w m wI 1 CONTAINER SEAM LOCATOR AND POSITIONER FOR CONTAINER PRINTING MACHINE One of the prime objects of the present invention is to pre-position cans in predetermined rotary positions on the mandrels which present them to the printing drum so that printing will always occur on the clear sur faces of the cans and never on the seams. Such seams normally are made up of ends having overlapping tabs, and present a rough and uneven surface which would, in short order, destroy the printing blankets. Moreover, the seams sometimes have solder deposits or weld material deposits, resulting from the particular joining operation which is employed, and do not present a smooth surface which can be legibly printed or decorated.

A further object of the invention is to provide simple and effective seam locating and positioning mechanism which is operative, without interrupting or slowing the high-speed printing operation, to preposition the cans on the mandrels, after they have been fed to the mandrels and before they reach the printing drum.

A further object of the invention is to design mechanism of the character described which is reliable and effective, and can be readily incorporated in existing container printing machine s.

A further object of the invention is to design mechanism of the character described which is capable of adjusting the position of the cans in a relatively short span of time during the travel of the mandrels from the container supply mechanism to the printing drum.

Other objects and advantages of the invention will be pointed out specifically. or will become apparent from the following description when it is considered in conjunction with the appended claims and the accompanying drawings, in which:

FIG. 1 is a schematic, side elevational view of a typical continuous printing machine showing the can positioning parts in interrelationship with the mandrel drum and printing drum;

FIG. 2 is an enlarged fragmentary, side elevational view, more particularly illustrating the can positioning mechanisms, the diagrammatic lines indicating in part the print assemblies which are removed from the view in the interests of clarity;

FIG. 3 is an enlarged, sectionalplan view taken on the line 3-3 of FIG. 2;

FIG. 4 is a still more enlarged, fragmentary, partly sectional, side elevational view of the mechanism within circle 4 in FIG. 2, with the can shown in section to indicate the manner in which the seam is located; and

FIG. 5 is an enlarged, fragmentary under-plan view taken on the line 55 of FIG. 2.

THE GENERAL DESCRIPTION Referring now more particularly to the accompanying drawings, and in the first instance to FIG. 1 thereof, the high-speed multi-color printing machine disclosed is of the general type shown and described in the present assignees copending application Ser. No. 708,690, entitled "Container Printing Machine and Method of Printing," filed Feb. 27, 1968, now U.S. Pat. No. 3,613,57l. While the machine depicted in FIG. 1 differs in detail to some extent from the machine described in the application mentioned, it is to be understood that the seam locating mechanism which is described and claimed may be incorporated with the machine disclosed in the application.

Broadly, the machine, as shown in FIG. 1, includes a frame F, a pair of side-by-side container supplying conveyor assemblies, each generally designated 10 at a loading station L, which include a double star wheel assembly, generally designated 11, as part of the mechanism for supplying containers C individually to laterally extending individual mandrels M mounted on mandrel assemblies, generally designated 12 (see FIG. 2), on a revolving mandrel drum, generally designated 13. In FIG. 1 the mandrel assemblies 12 are, for the most part, obscured by no print assemblies N which form no part of the present invention and will not be described. The mandrel drum 13 is mounted for rotation on a shaft 14 in line with a printing drum assembly, generally designated 15 which includes a printing drum 16 mounted for rotation on a shaft 17.

The printing drum 16 is revolved in timed relation with the mandrel drum 13 to print the containers at a printing station, generally designated P, betweenthe container loading mechanism 10 at the lower edge of drum l3 and a container unloading mechanism, generally designated 18 at the upper edge of drum 13. It is to be understood that a double line of containers is being supplied to the machine which, typically, may have a capacity in the neighborhood of 400 to 600 con tainers per minute. Typically, the containers will comprise metal cans C, including a side wall 19, having joined ends 19a and 1% which overlap, as shown in FIG. 4, to form a seam, generally designated S.

Since the present invention relates to the can positioning mechanism the other elements of the printing machine will be only summarily described. The application previously mentioned is incorporated herein by reference inasmuch as it described a printing and decorating machine of the character involved in detail.

THE CONTAINER SUPPLY CONVEYOR MECHANISM As FIG. 1 indicates, the cans C are fed to the machine via a pair of side-by-side chutes 20, each of which is provided with guide rails 21. Mounted above the pair of chutes 20, to separate the cans C are a pair of feed screws 22 journaled by bearing plates 23 at their ends which may be supported by a frame member 24. The star wheel assembly 11, which incorporates a pair of star wheels 25, is provided for receiving the separated cans C and is revolved in the direction of the arrow a on a shaft 26, which may be driven in timed relation with screws 22 and the drums l3 and 16 by a chain and sprocket mechanism, generally designated 27.

A curvilinear can guide bar 28, pivoted at 29 to the downstream end plate 23 is biased to move its free terminal end 28a laterally inwardly and gradually move the cans C onto the paired mandrels M as the pairs of mandrels M move on the drum 13 past loading station L. A spring-biased guide rod 28, which may be biased by a torsion spring provided on its pivot shaft mounting is provided at each side of the drum 13 to load cans C to each of the laterally in line, mandrels. Essentially the star wheel mechanism 11 delivers the cans C to a position laterally opposite the mandrels M proceeding on drum l3 and it is the guide rods 28 which then cause the cans C to telescope laterally over the mandrels M until they reach the laterally innermost position in which they are shown in FIG. 3. In addition, suction forces may be provided in the manner disclosed in the previously mentioned application to assist in drawing the containers C onto mandrels M.

THE PRINTING DRUM ASSEMBLY The printing drum assembly may be of exactly the character illustrated in the copending application mentioned and may comprise a pair of printing drums 16 rotatably supported for movement in the direction b. The drum shaft 17 may be driven by a pulley 29a via a timing belt 30 in the usual manner. Mounted on the drums 16 are the circumferentially spaced offset printing blankets 31 (see FIG. 2) which may be of the character described in the previously mentioned application and include an ink applying blanket portion and a trailing lacquer applying blanket portion. The blankets 31 in the machine, are of such length relative to the speeds of rotation chosen that each can C will be revolved through one complete revolution by the blankets and the containers will be printed over the desired circumferential surface by the particular blanket 31, in each color which is being used. The engaging surfaces of the various blanket portions 31 are so configured, in the usual manner, that no one color is in contact with another color, and there is no mixing of the inks. As the printing drum assembly 15 continues to move in the same direction of rotation, a lacquer may be applied by the trailing portions of each blanket to cover the inks printed with a fast-drying, clear, protective coating. The blankets 31 are, of course, formed of a resilient material such as natural or synthetic rubber which the ink and lacquer used do not attack. Ink supply and blanket coating assemblies, generally designated 32, for applying different colors of ink to each blanket 30, and a similar assembly 33, for applying the protective lacquer to the trailing portion of each blanket are provided in the usual manner. Each blanket 31 prints all colors and applies a coat of lacquer to a can C. It is to be understood that the assemblies 32 and 33 may be of the type mentioned in Jackson et al. US. Pat. No. 2,718,847, Munn U.S. Pat. No. 3,308,754 or I-Iovekamp U.S. Pat. No. 3,195,451, and, since they form no part of the present invention, will not be described in further detail.

THE MANDREL DRUM ASSEMBLY The mandrel drum assembly 13 comprises a circular disc 34, drivenby a pulley 35 fixed on shaft 14, via a timing belt 36 in the usual manner, in the direction of rotation c. As indicated previously, the drum carries a succession of circumferentially spaced mandrel assemblies 12 which are perhaps best illustrated in FIGS. 2 and 3. Radially extending support arms 37, provided on each side of the disc 34, are arranged in pairs so that each pair can mount a mandrel support arm 38. Each arm 38 is supported by a pivot shaft 39 from disc 34 and has a mandrel shaft 40 which projects laterally from both sides at its outer end. A mandrel M is mounted on the shaft 40 on each side of each arm 38 and comprises a sleeve 41 which has an enlarged diameter shouldered portion 41a at its inner end functioning as an axial stop for a can C which is telescoped over sleeve 41. Bearings 42 and 43 function to mount each mandrel sleeve 41 for rotation relative to the shaft 40, and cap members 44, secured by nuts 45, serve to maintain the mandrel parts in position. Each arm 38 is fixed to its pivotal pin 39 and, also fixed to each pin 39,

is'a trailing arm portion 46 connected by a coupling 47 to the piston rod 48 of a pressure fluid operated cylinder 49 supported on disc 34. The pressure fluid cylinders 49 are double-acting, solenoid operated, air cylinders which normally are operated to exert a retracting pull on the rods 48 and thus exert a radially inward pull on the arms 46. This, of course, tends to move the mandrels M radially outwardly since they are fixed to pins 39. Thus, each set of arms 38 and 46, and pin 39 function as bell crank levers to bias a can-carrying mandrel M outwardly to engage one of a pair of arcuate cam track 50. Also provided between the cam backs 50 is an arcuate cam track member 51, which also is supported on a frame part 52. It is the enlarged diameter inner portions 41a of each mandrel sleeve 41 which engage the twin cam tracks 50 and are responsible for revolving the mandrel sleeves 41 on the shafts 40 as the mandrel assemblies 12 traverse cam tracks 50. It will be observed that the earns 50 and 51 terminate short of the printing station P. The cam 51 extends between the earns 50 in position to be engaged by follower rollers 53 provided on arms 54 which are fixed to transversely extending shafts 55. Each shaft 55 is carried by plates 56 which fix to each side of arm 38 (see FIG. 5). At each end, each shaft 55 also mounts a lever 57 having a seam sensing or locating follower roler 58 which is rotatably mounted thereon via a pin 59. The levers 57 are fixed to the shaft 55. Also fixed to each shaft 55 is sh arm 60 in engagement with a coil spring 61 which normally tends to bias each of the arms 54 radially outwardly to the position in which arm 54 of the leading mandrel assembly 12 is shown at the printing station P in FIG. 2. A roller 54a is rotatably mounted on the arm 54 for engaging the arm 60 to compress the coil spring 61 when the follower rollers 53 traverse the cam 51.

Instead of the unloader mechanism described in the previously mentioned application, an alternate form of unloader mechanism is shown at 18 in FIG. 1. Inasmuch as the unloader mechanism forms no part of the instant invention, it' will not be described in detail. Briefly, it comprises a pair of laterally spaced, endless chains 62 carrying suction cup assemblies 63 which are alternately supplied with air or communicated with a vacuum source via lines 64, lines 64 communicating with a vacuum-air manifold of the type described in connection with the mandrel drum assembly in the aforementioned application.

The suction cups engage the ends of the cans on each pair of mandrels M and draw them endwisely off the mandrels at a time when lines 64 are in communication with a vacuum source. Later, when the suction cups are traveling along the upper runs of conveyor chains 62, air pressure is supplied to the lines 64 to discharge the cans to a suitable discharge conveyor (not shown).

THE DRIVE MECHANISM Except for unloading conveyor 18, the screws 22, and the star wheel assembly 25 which each are driven by separate motors, a drive motor 66 (FIG. 1) may be provided to perform the remaining drive functions. As FIG. 1 indicates, the motor 66 drives a drive pulley 67 on the input shaft 68 of a gear box 69 via drive belts 70. One output shaft 71 on the gear box 69 drives a jack shaft 72, which mounts a pulley 73 around which belt 36 is trained, via a drive belt 74. A second opposite output shaft (not shown) mounts a pulley (not shown) around which timing belt 30 is trained.

THE OPERATION In operation, two lines of containers or cans C are supplied by the pair of downwardly inclined chutes to the can separating screws 22 which lead to star wheel members 25. The cans are pushed laterally inwardly onto the pairs of mandrel sleeves 41 by the opposite guide bars 28. The screws 22, star wheels 25, and mandrel drum 13 are, of course, driven continuously in timed relation in a manner such that each mandrel sleeve 41 is loaded with a can C to be printed. The mechanism is assisted in loading the cans C to the mandrel sleeves 41 by suction forces applied through openings (not shown) in the shaft in the manner disclosed in the aforementioned application.

As a particular mandrel assembly 12 approaches the cam tracks 50, the enlarged portions 41a of can supporting mandrel sleeves 41 engage the cam surfaces 50 and are revolved thereby on rods 40 about their axes. At the same time, the roller 53 on each mandrel assembly 12 engages the intermediate cam track 51 which forces each associated roller 58 to engage the periphery of the can C on the associated mandrel M. As the mandrels M continue to be spun, the rollers 58 will eventually come into engagement with the seams S which will prevent the containers C from rotating further with mandrel sleeves 41. As FIG. 4 illustrates, the biasing force exerted by cam 51 is sufficient to depress even a can with an inset seam slightly adjacent the seam to form aridge which prevents the can C and mandrel sleeve 41 from rotating further. During the remainder of the journey of each mandrel assembly 12 along the earns 50, the portions 410 of mandrel sleeves 41 will then simply slide on surfaces 50 and will not be rotated thereby. Since rollers 58 rotate independently, the rolleron each end of each shaft 55 is free to locate the seam on the can C it engages.

During the time that rollers 58 are being pressed by the cam 51 into engagement with the peripheries of containers C, the biasing cylinders 49 maintain a constant force on arms 38 maintaining the portions 41a of mandrel sleeves 41 in engagement with cam surfaces 50. When the particular mandrel assembly 12 clears the cams 50, however, the associated biasing cylinder 49 is free to move the trailing arm 46 slightly inwardly to a position such that the cans C on mandrels M will engage the printing blankets 31 with sufficient pressure to be rotated thereby about the axis of rods '40 and be printed. inasmuch as the rollers 58 have pre-located the seams S, printing will always commence at a time when each seam S has been revolved around to a position such that it initially clears the printing portion of the printing blanket 31, the. initial portions of blankets 31 being in the present embodiment free of ink to provide a sufficient lead time for some non-printing rotation to occur.

When the lever 54 of each mandrel assembly 12 clears cam 51, the associated return spring 61 forces the arm 60 outwardly to insure that the same locating rollers 58 are removed from the containers C and will not re-engage the containers C to interfere with the printing operation. It is the roller 54a of each assembly (FIG. 5) which normally bears on arm 60 to compress the spring 61 during the time the particular mandrel assembly 12 is traversing the cam 51. In some instances, the seams S will protrude peripherally, of course, and in this case the overlapped edges will operate in a similar manner to engage rollers 58 and be held thereby to prevent further rotation of containers C and mandrel sleeves 41 from occurring.

As indicated previously, the mandrels M are caused to make more than one, and preferably two revolutions, as they pass a blanket 31. During the first revolution, the containers revolve relative to blanket 31 and will be printed. During the second revolution, the containers C are in engagement with the lacquer applying portion of the blanket and a protective fast-drying lacquer will be applied over the ink. As in the previously mentioned application, raised drive strips (not shown) may be provided in conjunction with each printing blanket 31 for engaging the enlarged diameter portions 41a of mandrel sleeves 41 to positively drive the mandrel sleeves at printing station P. The mandrels float in the sense that the pressure cylinders 41 permit them to adapt to the printing drum blankets 31, which act as cams to revolve them. The drum 16 travelsin timed relation with, but much faster, than the drum 13. Once the printing is accomplished at printing station P, the mandrels travel to the unloader 18 which unloads them in the manner previously described.

It is to be understood that the drawings and descriptivematter are in all cases to be interpreted as merely illustrative of the principles of the invention, rather than as limiting the same in any way, since it is contemplated that various changes may be made in various elements to achieve like results without departing from the spirit of the invention or the 'scope' of the appended means mounted on said carrier in association with said mandrels for locating said seams or obstruction portions and prepositioning said container parts relative to said printing blanket means so that only predetermined portions of the container parts are printed, including- :releasable stop means mounted on said carrier adjacent said mandrels; means for holding said stop means in a seam engaging position projecting into the paths of said seams or obstructions; means for rotating said container parts to bring the seamsinto'engagement with the stop means; and means for maintaining said stop means in said seam engaging position after said seams have been engaged by said stop means and until said printing station is reached to positively interrupt rotation of said container parts until the printing station is reached. i

2. The combination defined in claim 1 in which said stop means comprises sensing rollers, biased into engagement with the side walls of the container parts.

3. The combination defined in claim 2 in which stationary track means are provided'along the said path of travel upstream from the printing station for biasing the stop means in a direction toward the container parts on the mandrels.

4. High speed printing or decorating apparatus for container part side walls and the like having generally longitudinally disposed seams or obstruction portions including: a carrier, having a series of spaced, laterally projecting container part receiving, non-driven mandrels thereon, movable in a continuous path of travel; said carrier including laterally projecting mandrel supports and said mandrels being freely rotatably mounted on said mandrel supports for rotation in a continuous path of travel opposite the direction of travel of said carrier; means mounted adjacent the carrier presenting offset printing blanket means at a printing station past which said mandrels move; means for supporting the container parts; transfer means mounted opposite the path of travel of the mandrels for transferring container parts between the mandrels and said support means; and means mounted on said carrier in association with said mandrels for locating said seams or obstruction portions and prepositioning said container parts relative to said printing blanket means so that only predetermined portions of the container parts are printed, includingzstops on the carrier associated with the mandrels for halting the container parts; and stationary cam means commencing upstream of said printing station and tenninating just short of said printing station disposed in position to be engaged by the mandrels as they move toward the printing station for revolving the container parts and mandrels in the same direction on the mandrel supports and bringing the seams in the container parts into engagement with said stops.

5. High speed printing or decorating apparatus for container part side walls and the like having generally longitudinally disposed scams or obstruction portions including: a carrier, having a series of spaced, laterally projecting container part receiving mandrels thereon, movable in a continuous path of travel; means mounted adjacent the carrier presenting offset printing blanket meansat a printing station past which said mandrels move; means for supporting the container parts; transfer means mounted opposite the path of travel of the mandrels for transferring container parts between the mandrels and said support means; and means mounted on said carrier in association with said mandrels for locating said seams or obstruction portions and prepositioning said container parts relative to said printing blanket means so that only predetermined portions of the container parts are printed including seam sensing stop means mounted on said carrier adjacent each mandrel for movement between a radially outer position removed from a mandrel supported container part and a radially inner position engaging the exterior surface of the container part side wall, and cam means in the path of at least a portion of said seam sensing stop means moving with said carrier for moving said seam sensing stop means to said radially inner position engaged with the exterior surface of a mandrel supported container part.

6. The apparatus set forth in claim 5 wherein means is provided for driving said printing drum and said carrier drum in the same direction of rotation such that engagement of the container parts with the blanket means at the printing station causes said container parts to be revolved in an opposite direction.

7. The apparatus set forth in claim 1 wherein each seam sensing stop means comprises a projecting lever with a stop part thereon; yieldable means normally urging said stop part to a position removed from said mandrel, said cam means being positioned to bias each lever in a direction opposing said yieldable means to maintain said stop means in engagement with the container part on each mandrel during a portion of its travel with said carrier, but releasing said stop means, upstream of said printing station, permitting said stop means to return to said radially outer position.

8. The combination defined in claim 7 in which said mandrels are carried in pairs on said carrier; and said locating and prepositioning means includes: a roller for engaging the container part on each mandrel and a common cam mechanism for biasing each roller into engagement with the container part upstream of the printing station; said rollers being positioned with respect to the printing blanket means such that the nonseamed portions of the container parts only are printed or decorated.

9. The combination defined in claim 5 in which said mandrels are rotatably mounted on the said lever assemblies and the container parts are frictionally received on the mandrels in a manner such that they nor mally are retained in rotary position thereon, but may be rotated on said mandrels.

10. The combination defined in claim 9 in which said means mounted on said carrier for locating said seams or obstruction portions and prepositioning said container parts includes stop assemblies supported on each mandrel supporting lever assembly.

11. The combination defined in claim 10 in which each stop assembly comprises a projecting lever with a stop part thereon; and means for biasing each lever in a direction such that each said stop part is maintained in engagement with the container part on each mandrel during a portion of its travel with said carrier.

12. The combination defined in claim 11 in which return spring means for each stop assembly, normally overcome by said latter biasing means, is freed just upstream from the printing station to positively remove each stop part to a position in which it does not interfere with printing rotation of the container parts on the mandrels.

13. The combination defined in claim 12 in which said stop means assemblies include follower rollers and said biasing means includes a curvilinear stationary cam located upstream of the printing station and engaged by the follower rollers to urge said stop parts to engage the side walls of the container parts and locate the scams or obstruction portions thereon.

* I I k 

1. High speed printing or decorating apparatus for container part side walls and the like having generally longitudinally disposed seams or obstruction portions comprising: a carrier, having a series of spaced, laterally projecting container part receiving mandrels thereon, movable in an endless path of travel; means mounted adjacent the carrier presenting offset printing blanket means at a printing station past which said mandrels move; means for supporting the container parts; transfer means mounted opposite the path of travel of the mandrels for transferring container parts between the mandrels and said support means; and means mounted on said carrier in association with said mandrels for locating said seams or obstruction portions and prepositioning said container parts relative to said printing blanket means so that only predetermined portions of the container parts are printed, including:releasable stop means mounted on said carrier adjacent said mandrels; means for holding said stop means in a seam engaging position projecting into the paths of said seams or obstructions; means for rotating said container parts to bring the seams into engagement with the stop means; and means for maintaining said stop means in said seam engaging position after said seams have been engaged by said stop means and until said printing station is reached to positively interrupt rotation of said container parts until the printing station is reached.
 2. The combination defined in claim 1 in which said stop means comprises sensing rollers, biased into engagement with the side walls of the container parts.
 3. The combination defined in claim 2 in which stationary track means are provided along the said path of travel upstream from the printing station for biasing the stop means in a direction toward the container parts on the mandrels.
 4. High speed printing or decorating apparatus for container part side walls and the like having generally longitudinally disposed seams or obstruction portions including: a carrier, having a series of spaced, laterally projecting container part receiving, non-driven mandrels thereon, movable in a continuous path of travel; said carrier including laterally projecting mandrel supports and said mandrels being freely rotatably mounted on said mandrel supports for rotation in a continuous path of travel opposite the direction of travel of said carrier; means mounted adjacent the carrier presenting offset printing blanket means at a printing station past which said mandrels move; means for supporting the container parts; transfer means mounted opposite the path of travel of the mandrels for transferring container parts between the mandrels and said support means; and means mounted on said carrier in association with said mandrels for locating said seams or obstruction portions and prepositioning said container parts relative to said printing blanket means so that only predetermined portions of the container parts are printed, including:stops on the carrier associated with the mandrels for halting the container parts; and stationary cam means commencing upstream of said printing station and terminating just short Of said printing station disposed in position to be engaged by the mandrels as they move toward the printing station for revolving the container parts and mandrels in the same direction on the mandrel supports and bringing the seams in the container parts into engagement with said stops.
 5. High speed printing or decorating apparatus for container part side walls and the like having generally longitudinally disposed seams or obstruction portions including: a carrier, having a series of spaced, laterally projecting container part receiving mandrels thereon, movable in a continuous path of travel; means mounted adjacent the carrier presenting offset printing blanket means at a printing station past which said mandrels move; means for supporting the container parts; transfer means mounted opposite the path of travel of the mandrels for transferring container parts between the mandrels and said support means; and means mounted on said carrier in association with said mandrels for locating said seams or obstruction portions and prepositioning said container parts relative to said printing blanket means so that only predetermined portions of the container parts are printed including seam sensing stop means mounted on said carrier adjacent each mandrel for movement between a radially outer position removed from a mandrel supported container part and a radially inner position engaging the exterior surface of the container part side wall, and cam means in the path of at least a portion of said seam sensing stop means moving with said carrier for moving said seam sensing stop means to said radially inner position engaged with the exterior surface of a mandrel supported container part.
 6. The apparatus set forth in claim 5 wherein means is provided for driving said printing drum and said carrier drum in the same direction of rotation such that engagement of the container parts with the blanket means at the printing station causes said container parts to be revolved in an opposite direction.
 7. The apparatus set forth in claim 1 wherein each seam sensing stop means comprises a projecting lever with a stop part thereon; yieldable means normally urging said stop part to a position removed from said mandrel, said cam means being positioned to bias each lever in a direction opposing said yieldable means to maintain said stop means in engagement with the container part on each mandrel during a portion of its travel with said carrier, but releasing said stop means, upstream of said printing station, permitting said stop means to return to said radially outer position.
 8. The combination defined in claim 7 in which said mandrels are carried in pairs on said carrier; and said locating and prepositioning means includes: a roller for engaging the container part on each mandrel and a common cam mechanism for biasing each roller into engagement with the container part upstream of the printing station; said rollers being positioned with respect to the printing blanket means such that the non-seamed portions of the container parts only are printed or decorated.
 9. The combination defined in claim 5 in which said mandrels are rotatably mounted on the said lever assemblies and the container parts are frictionally received on the mandrels in a manner such that they normally are retained in rotary position thereon, but may be rotated on said mandrels.
 10. The combination defined in claim 9 in which said means mounted on said carrier for locating said seams or obstruction portions and prepositioning said container parts includes stop assemblies supported on each mandrel supporting lever assembly.
 11. The combination defined in claim 10 in which each stop assembly comprises a projecting lever with a stop part thereon; and means for biasing each lever in a direction such that each said stop part is maintained in engagement with the container part on each mandrel during a portion of its travel with said carrier.
 12. The combination defined in claim 11 in which retUrn spring means for each stop assembly, normally overcome by said latter biasing means, is freed just upstream from the printing station to positively remove each stop part to a position in which it does not interfere with printing rotation of the container parts on the mandrels.
 13. The combination defined in claim 12 in which said stop means assemblies include follower rollers and said biasing means includes a curvilinear stationary cam located upstream of the printing station and engaged by the follower rollers to urge said stop parts to engage the side walls of the container parts and locate the seams or obstruction portions thereon. 